Multinational drone services group Delta Drone International is venturing into drone inspections on concentrated solar power (CSP) thermal systems – which is “highly niche”, says Delta Drone South Africa group sales and marketing head Camron Pfafferott.

CSP systems differ from solar photovoltaic (PV) power systems in that, while PV systems generate electric power directly using solar cells to convert energy from the sun into a flow of electrons, CSP plants use mirrors to concentrate the sun’s heat to drive traditional steam turbines or engines that create electricity. The thermal energy concentrated in a CSP plant can also be stored and used to produce electricity when it is needed, even at night.

CSP systems are attractive options for large-scale power generation because thermal energy storage technologies are more efficient than electricity storage technologies such as batteries.

Therefore, the energy storage capabilities of CSP systems can improve not only financial performance but also the dispatchability of solar power and flexibility within the power network.

“There is a lot of effort and money going into developing solutions for solar PV plants, but not as much emphasis has been placed on developing solutions for CSP plants. This is mainly due to the limitations that mirrors pose on photogrammetry I think the solar power industry would benefit vastly from customised drone inspections, for the CSP subsector,” says Delta Drone International subsidiary Rocketfarm business head Zander van Pletzen, who claims that there are no other UAV inspection service providers truly servicing CSP plants.

CSP plants are typically large and comprise tens of thousands of heliostat mirrors, as well as a large solar tower and thermal storage plant in the centre.

The largest single-site CSP plant globally is the Mohammed bin Rashid Al Maktoum Solar Park in Dubai, United Arab Emirates (UAE), which was scheduled for completion by the end of last year.

According to the Dubai Electricity and Water Authority, the 44 km2 solar park comprises 250 MW PV capacity and a 700 MW CSP plant. The plant features the tallest solar tower globally at 260 m using 70 000 heliostat mirrors to collect thermal energy. It also has the largest thermal storage capacity globally of up to 15 hours.

In CSP plants such as this, any number of heliostat mirrors could suffer from cracks or other kinds of obstructions – such as dust build-up – that could lead to heat and efficiency losses, Van Pletzen says.

Moreover, the heat collection vacuum pipes on the central tower need to be monitored to ensure that they are in good working order to eliminate vacuum losses.

He mentions that the plants the company is currently working on do not have a central tower but have heat collection elements running over the parabolic trough collectors. “These heat collection elements need to be checked for vacuum loss to prevent inefficiency.”

The labour required to inspect such a large site thoroughly would be significant and time consuming. Inspection Benefits Additionally, the maintenance costs are also enormous on these type of plants so it is vital that the efforts to resolve these issues are focused and done in a timely manner.

“Drone inspection services can cover the large footprint of a CSP plant in a comparatively short time and provide highly accurate locations of problems to ensure efficiency and overall production integrity,” Van Pletzen says, adding that the service will also mitigate any safety risks involved in CSP plant inspections.

The CSP plant drone inspection service, chiefly in the research and development stage, will be released officially on the market “soon”, he assures, and invites interested plants to make contact.

engineeringnews